How to solve the thermal runaway of lithium batteries?

What is the reason for the thermal runaway of lithium batteries, and how to solve the thermal runaway of lithium batteries ?

Thermal runaway of lithium batteries is a very dangerous thing, so it is also more important to understand the reasons for thermal runaway and the solutions. It is necessary to pay attention to prevent the occurrence of thermal runaway.

The reasons for thermal runaway of lithium batteries are as follows:

1. External influence

Under the influence of external force, the lithium battery is affected and deformed, and different parts of itself undergo relative displacement, and the lithium battery is subjected to external force to cause internal collision, extrusion and puncture. z is the most dangerous puncture. The conductor is inserted into the battery body, causing a direct short circuit of the positive and negative electrodes. Compared with the probabilistic internal short circuit such as collision and extrusion, the heat generation during the puncture process is more severe, and the probability of thermal runaway is higher. .

2. Irregular use

Irregular use of lithium batteries generally includes external short circuit, overcharge, overdischarge and other forms, of which the most likely to develop into thermal runaway is overcharge. External short circuit: An external short circuit occurs when two conductors with a voltage difference are connected outside the cell. from external short circuit to thermal runaway, in

An important link between the temperature is too high. When the heat generated by the external short circuit cannot be dissipated well, the temperature of the lithium battery will rise, and the high temperature will trigger thermal runaway.

Overcharging: Due to the presence of high electricity, heat and gas are several common characteristics in the overcharging process. Heat generation comes from ohmic heat and side reactions.

Overdischarge: Unlike the above situations, the potential danger is much higher than people think. The dissolution of copper ions induced by overdischarge migrates through the membrane and forms copper dendrites with lower potential on the cathode side. With increasing growth, copper dendrites may penetrate the separator, leading to severe thermal runaway problems.

3. Use in high temperature environment

It is rare that the operating environment temperature is too high, but high temperature is a link that directly triggers thermal runaway. The solution to thermal runaway of lithium battery is as follows:

1. Thermal runaway caused by external force: The best way to deal with it is to replace the faulty lithium battery and remove the damaged lithium battery in the whole.

2. Thermal runaway caused by external short circuit: When the heat cannot be dissipated well, the temperature of the lithium battery will rise rapidly, and the high temperature will cause thermal runaway. Therefore, cutting off the short-circuit current or cooling down is the method to suppress the thermal runaway caused by the external short-circuit. Reasons and solutions for thermal runaway of lithium batteries. When the lithium battery is thermally out of control due to certain factors, the circuit should be cut off immediately and corresponding protective measures should be taken. When using a larger lithium battery pack, charge and discharge should be regulated to avoid the problem of thermal runaway.